My understanding is The Constitution of the United States allows treaties signed by the President and ratified by the Senate are part of the "supreme Law of the Land."
The United Nations Charter, which the United States wrote in large part, and signed and ratified as a treaty in 1945. Not only is the UN Charter it an international treaty signed by the US to take part in it is also tied into your constitution.
Except in response to an armed attack, Nations can not threaten or engage in warfare without the authorization of the UN Security Council.
Your President swore to uphold and defend the Constitution. Yet he claims the right to ignore your treaty obligations and instigate a war with Iraq, with or without the approval of the United Nations.
The crimes hereinafter set out are punishable as crimes under international law:
(a) Crimes against peace:
(i) Planning, preparation, initiation or waging of a war of aggression or a war in violation of international treaties, agreements or assurances;
(ii) Participation in a common plan or conspiracy for the accomplishment of any of the acts mentioned under (i).
(b) War crimes:
Violations of the laws or customs of war which include, but are not limited to, murder, ill-treatment or deportation to slave-labour or for any other purpose of civilian population of or in occupied territory; murder or ill-treatment of prisoners of war, of persons on the Seas, killing of hostages, plunder of public or private property, wanton destruction of cities, towns, or villages, or devastation not justified by military necessity.
(c) Crimes against humanity:
Murder, extermination, enslavement, deportation and other inhuman acts done against any civilian population, or persecutions on political, racial or religious grounds, when such acts are done or such persecutions are carried on in execution of or in connection with any crime against peace or any war crime.
Complicity in the commission of a crime against peace, a war crime, or a crime against humanity as set forth in Principle VI is a crime under international law.